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I J. D. .SIBIIEY, 0.! HIDDLE TOWN, GONNEOTIGU'L' ZettmPeteat m. mammal.as, me.

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I re am. waou 11' IA! 'eozvernm I Do it hnow'n that I, J. D. Sum, ofMiddletown, coanty of Middleacx, and State of Connecticut, haveiaventedaa Improved Spirit-Level; and I hereby declare the following tobe an exact deacription thereof,

reference bell had to the accompanying drawinge, and to the lottora oireference marlred thereon, mahin a pert of thie apecileatien, in which-Figure 1 repreaeata e perapeetive view oi the inatrament.

Figure 8, the pivotvapon which it operatee. I

level-frame.

'lilare trepreeeate a aide view oi-the level. I The nature of theinvention eonaiata in the movable. eigbte attached to tho. enda'oi anyepirit-level -i'ramc,

" with a central pivot and circular diah for the level. to revolve upon,the pivot being hollow, (or the purpoee oi I eaepeeding a plummet-lineand plamb attached. I

A repreeenta a circular diah or here, made of wood or metal. 0n theaide: are marked the anglca of degrees. In the centre of thin horizontaldiah ia a hollow pivot, 13, and in the centre of a cnrpontcr'e ortnaaon'e ordinary apiritdevei I place a metallic eoeltet, C, to operateon the pivot B. I

On each and of the eplrit-level frame I attach aqaare metallic platea DD, with two groovoe, E, in the top of the platee. Upon thoae platea D D,I ll: two aighta-one with the pin-hole eye-eight G, and the other,alight, H, with two wire eroea-liaee, one a perpendicular and the othera horizontal line.

ll'he haaea of theee alghte G and II have flangee on their lower edger,to ac to alide in the groovee E, in the platen D D, to alwaya maintaintheir proper poaitiona. They are then firmly l'aatened, by a'erewe J J,to the epirit-level frame K.

On the upper aide, and at the centre oi the apirit-level frame K, ietheimnmn" on-1...: tube 1...

I at rl ht aelea with the epirit-level L ie the epirit-level tube M,eomlnoniy called the perpendicular level, a I a I te earpenterflermaaeaa' ordinary ieveia. I The red llnea acroaa the dick A ahow how theapirit-lcvel frame K can be revolved at any angle from the peiat ofeight.

The advantage of my invention ie, that more accurate levelling can beexecuted than heretofore, with a carpeater'e erdiaary level, for ehortdietaneea, and at a very trifling eapenae. There aighte, being movable,can be attached teeny earpentere ordinary spirit-level, and incombination with the aoelret 0, pi'vot B, and circular dick orheriaentel plate A, al'ord a very cheap and uaei'ul inetrument forcarpentore' and meeona' uses, and to timple in conatrnction that theyonngeat apprentice ca n acoompliah the most accurate levelling.

What I claim a my invention,'anddeaire to accure by Lcttc ra'Pat ent,ia- I l'he combination of the revolving aigbted level with the dial: A,when arranged and operating as herein deeerihed, ead for the parpeaeeeet i'ortin. I J. D. 8

Wltaeaeeet War. 11. Anna, Kroner. SIIOII.

Figure 8 ahowa the eh'ape and eonatrnctien oi the aighte, and the mannerin which they are attached to the

